Tony Stark broke from his team of Avengers this weekend to propel Iron Man 3 to the second largest debut in Hollywood history, nabbing $175.3 million, according to studio estimates from box office tracking firm Hollywood.com.

If estimates hold Monday, IM3 will be second only to The Avengers, which opened to $207 million last year.

Analysts say that, in addition to securing its place in the record books, IM3 gave the box office a much-needed shot in the arm to begin the Hollywood summer, which runs from the first weekend in May to the Labor Day weekend and accounts for more than 40% of studios' business for the entire year.

"The terrible run of 2013 releases ended" this weekend, says David Mumpower of Boxofficeprophets.com. "Iron Man 3 behaved like a box office black hole, mercilessly devouring the other films."

Critics and fans wolfed down the superhero story. About 78% of critics recommended the movie, while 83% of moviegoers liked it, according to pollsters RottenTomatoes.com.

Internationally, the film has been a hit for weeks, and IM3's worldwide haul rose to $680.1 million. IMAX reported a record haul as well, collecting $16.5 million domestically and $13 million internationally.

Ray Subers of Box Office Mojo says that IM3 flourished because moviegoers didn't consider it a continuation of Iron Man 2, the 2010 sequel that did $312 million but was pummeled by critics and fanboys.

The latest film trounced the $128 million debut of Iron Man 2 and should easily surpass its predecessor, which went quickly forgotten by audiences, Subers says.

"With very few exceptions, the third entry in an ongoing franchise winds up grossing less than its predecessor, no matter how well-liked the predecessor was," Subers says. "That probably won't be the case with Iron Man 3, though, because it's being perceived as a follow-up to The Avengers, not to Iron Man 2."

The gargantuan haul left only scraps for holdover films. Michael Bay's action comedy Pain & Gain took second place with $7.6 million, followed by the Jackie Robinson story 42 with $6.2 million.

Tom Cruise's Oblivion was fourth with $5.8 million, while the animated comedy The Croods rounded out the top 5 with $4.2 million.